Binding compound and process of making same.



ARCHIBALD CLAUDE EVANS, OF HAMPTON WIGK AND IE'EIIRGY J'OSIlil MITCHELL,0F WESTMINSTER, LONDON, ENGLAND.

BINDING COMPOUND AND PROCESS OF MAKING SAME.

N0 Drawing.

To all whom it may concern:

Be it known that we, ARGHIBALD CLAUDE EVANS and PERCY J osii MirroHELL,residing at Hampton Wick, Middlesex, England, and Westminster, London,England, respectivel have invented certain new and useful mprovements inBinding Compounds and Processes of Making Same; and we do hereby declarethe following tobe a full, clear, and exact description of theinvention, such as will enable others skilled'in the art to which it'appertains to make and use the same. I

Thisinvention relates to a new and improved binding material for use inbriqueting, road making and the like applications and comprises aprocess for producing same.

Heretofore tar pitch has been thebinding agent or ingredient mostlyemployed for the purpose of making fuel briquets from coal, and whileits use is very effective for such purpose the same is attended by anumber of disadvantages. Among these may be mentioned firstly the factthat operatives employed in the process using pitch are subject to pitchcancer, and skin troubles the presence of the phenols in the finisheddue probably to the presence of phenols or phenol derivatives whichescape from the molten compound. A further disadvantage is that in orderto obtain the pitch the' tar has to be subjected to a prolonged andtherefore costly process of distillation before it will yield asubstance that will set to a sulficient hardness when cold. Thenecessity of carrying out this distillation accounts for product, the.reason being that although these phenols are removed in the earlierstages of distillation it is necessary -to introduce a portion of thefirst runnings into the i still at the close of the distillation inorder to be ableto withdraw the thick pitch which 5 remains, and it isin this way that the phenols are introduced into the product.

Processeshave already been proposed for solidifying tar by heating it ina still to a I temperature not exceeding 360- F. and after coolingadding to it considerable quantities of sulfuric acid, these quantitiesvarying am such Previously known processes in that in i" v .the latterpractically the whole of the solidifying is e from a minimum of 3% to amaximum of The present invention differs from ected by means of aconsiderable Specification of Letters Patent. Patented Deg, 26, 1191108,Application filed September 7, 1915. Serial in. 49,349.

quantity of sulfuric acid, while in the former the solidification iseffected principally by the addition of a considerable quantity ofcarbon, while only an exceedingly small quantity of sulfuric acid isused at the end of the process; it will thus be apparent that thematerial obtained according to the prescut invention will be of anentirely different tar would yield in the ordinary-way. The

phenols removed in the earlier distillation are not re-introduced intothe product and the process also provides means for regulating( theultimate consistency and binding properties of the finished product.

The invention carried out as follows: The starting out material ispreferably coal tar in the condition. in which the same is usuallyobtained from gas works except that most of the ammonia may have beenremoved from the tar before use. The tar is distilled at a temperatureof 270? in a suitable retort or still. The latter may be of anyconvenient'type but should be fitted with a man-hole capable of beinghermetically closed and should further be provided with a mechanicalstirring device. The heating arrangements consist preferably of afurnace provided with the usual fines which should be so arranged thatthe heat can be shut 011' at any desired moment, so as to ,palpablefomnis now gradually added and stirred into the mass. The reason-why thisoperation must not be carried out at a temperature above 250 C. is, thatas the man- The hole must be opened for the purpose the tar and coaldust would be liable to catch fire if this temperature were exceeded.The coal used should preferably be of high volatile contents and theamount added may be va- .ture raised to a minimum of 270 stirring beingcontinuedthe whole time; the content is kept at that temperature or notlower than that temperature until the added coal or like material beginsto soften and give off its volatile contents. As soon as this actionstarts the heat is immediately shut off and the material is allowed tocool as rapidly as possible to a temperature below 100 0. If desired thematerial can be pumped into a tank or like vessel for this cooling totake place. At this stage 0.25% to 1.9 0 of sulfuric acid of a preferredstrength of 170 Twaddle is gradually added and intimately mixed with thematerial and if this operation is carried out in a secondtank the lattershould be provided with suitable stirring or agitating means. Care mustbe taken that the temperature of the mixture while the sulfuric acid isbeing added does not rise above 100 0. nor fall below 49 0. After theacid to its measure has been added and thoroughly stirred in the-hotmass is run off and allowed to cool and solidify in any suitable moldsor other receptacles convenient for the purpose.'

In lieu of coal tar, shale oil, or any other similar mineral oil may beused, and in the treatment of the same for the purpose of this inventionthe light volatile oils are dis tilled off until the residue is of aboutthe same consistency as that of the tar previously referred to at atemperature of 270. 0. after the same has been distilled at thattemperature in the manner described. The subsequent manufacture of thecompound is identical with that described in the case of coal tar. Alsoin place ,of sulfuric acid, chlorid of sulfur or other known thickeningagent may be employed, but sulfuric acid will generally be found to bepreferable, owing to the ease with which it can be procured and owing tothe fact that it is less unpleasant to handle than the other known andhitherto used thickening agents.

By the above described means a material is produced which resemblespitch and has similar softening and melting points, while itsvaporization point is about 0. higher than that of most of the ordinarycommercial medium pitches usually sold for briqueting purposes. Theyield of ordinary pitch from-ordinary coal tar is about 5 tons from 10tons of tar, while accordin to the invention 8 tons and 16 cwt. ofbinding agent can be roduced from 10 tons of tar. part from the otherpreviously described advantages of this invention it will be seen that amaterial which solidifies into a pitch like substance which melts andsoftens at similar temperatures to pitch is obtained without thenecessity of carrying the distillation of the tar to anything like thesame stage. A further advantage is that the consistency of the finalproduct can be controlled within reasonable limits by the amount ofloading material added. It will also be seen that the objectionableaddition of the light oils containing phenols which is usual in theordinary production of pitch is obviated according to this invention andthat the finished product is free from or practically free from phenolswhich pass over during the first distillation.

We claim 1. A process for the manufacture of binding materials forbriqueting, road making and the like which includes removing the lightoils from coal tar, treating saidtar while hot with finely divided coaldust or hydrocarbon soot, cooling the resulting product to 100 0. andthen treating with a small quantity of thickening agent.

2. A process for manufacturing binding materials for briqueting, roadmaking and the like which includes distilling coal tar at a temperatureof 270 0. until the light oils have been removed, cooling the product toapproximately 250 0., adding finely divided coal dust or hydrocarbonsoot, stirring the mixture and heating to a minimum temperature of 27 00. until the volatile matter begins to pass off from the added material,cooling the mixture to 100 0. nd adding a small quantity of sulfuricacid or a specified equivalent thickening agent.

3. A process for the manufacture of binding materials for briqueting,road making and the like which includes removing the light oils fromshale oil distillate or its specified equivalent, treating the samewhile hot with finely divided coal dust or its specified equivalent,cooling the mixture to 100 0., and adding a small quantity of sulfuricacid or its specified equivalent thickening agent.

4:. A process for the manufacture of binding materials for briqueting,road making and the like which includes distilling shale oil distillateor its specified equivalent at a temperature of 270 0. until the lightoils have been removed, cooling the product to approximately 250 0.,adding finely divided coal dust or its specified equivalent,

thoroughly stirring the mixture and heating the same to a minimumtemperature of 27 0 0., maintaining the temperature of 270 0.

road making and the like consisting of the residue from coal tar afterthe light oils have been removed, said residue being thickened with coaldust or its specified equivalent and a small quantity of sulfuric acidor its specified equivalent. A

In testimony whereof we aflix our signatures in presence of twowitnesses.

ARCHIBALD CLAUDE EVANS. PERCY JOSE MITCHELL.

Witnesses:

FRANK B. DEHN. ALBERT R. RAMSEY.

